Wide field of view imaging with parabolic cylindrical reflectors

Parabolic cylindrical reflectors (PCRs) can have a large field of view, for example a 15 m reflector can access an area of 1° by 120° at 1.4 GHz. It is seen that the radiation pattern is asymmetric. This causes problems in situations where the radiation pattern rotates with time, such as radio astronomy. The rotation of the radiation pattern limits the field of view. In this paper a normalized signal to noise ratio is calculated for a full observation and this is then used to determine the field of view. The greatest variation occurs where the radiation pattern of a single feed element is used. The variation is reduced by RF beamforming. If the radiation pattern has an aspect ratio of 2.5:1 the observed field of view is approximately constant and has a value that is three times larger than that of an equivalent parabolic dish.